Evaluation of an alternative HIV diagnostic algorithm using specimens from seroconversion panels and persons with established HIV infections
ABSTRACT The current algorithm for HIV diagnosis in the US involves screening with an immunoassay (IA) and supplemental testing with Western blot (WB) or immunofluorescence assay. Because of existence of more sensitive and specific FDA-approved assays that would also reduce the cost and turn-around time of testing compared to WB, several alternative algorithms have been evaluated. Recently, an alternative algorithm using a sensitive 3rd or 4th generation IA followed by an HIV-1 and HIV-2 discriminatory supplemental test on the initial IA-positive specimens was proposed. Concordant positive results indicate HIV-positive specimens and discordant results are resolved by nucleic acid amplification testing (NAAT).
To evaluate the sensitivity of assays during acute HIV infection and the performance of the current and an alternative algorithm using samples from HIV-1 seroconversion panels and persons with established HIV infections.
To evaluate the algorithms in early infections, 26 HIV-1 seroconverters from the US were tested with three 3rd generation and one 4th generation IA, six rapid tests (RTs), one NAAT, and WB. Sensitivity and specificity of the algorithms were calculated by testing an additional 416 HIV-positive and 414 uninfected control samples with one 3rd generation and one 4th generation IA, four RTs, one NAAT, and WB.
The individual assays evaluated became positive 5 (RT) to 26 days (NAAT) before WB was positive. Among seroconverters, the alternative algorithm detected significantly more infections than the current algorithm (103-134 versus 56, p<0.0001). Furthermore, the use of a 4th generation IA instead of a 3rd generation assay as the screen resulted in significantly higher detection of acute infections (p<0.0001). In contrast, the algorithms performed equally among specimens from established HIV-1 infections.
This study demonstrated improved sensitivity of the alternative algorithm for detecting acute HIV-1 infections, while maintaining the ability to accurately detect established HIV-1 infections. Early detection is important as individuals can be highly infectious during acute infection. In addition, the alternative algorithm should reduce turn-around time by using a RT as the supplemental test has the potential to increase the number of test results returned.
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ABSTRACT: Cross-sectional HIV incidence surveillance, using assays that distinguish 'recent' from 'nonrecent' infections, has been hampered by inadequate performance and characterization of incidence assays. In this study, the Consortium for the Evaluation and Performance of HIV Incidence Assays presents results of the first independent evaluation of five incidence assays (BED, limiting antigen avidity, less-sensitive Vitros, Vitros avidity and BioRad avidity).AIDS (London, England) 08/2014; 28(16). DOI:10.1097/QAD.0000000000000429 · 6.56 Impact Factor
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ABSTRACT: Approximately 60% of human immunodeficiency virus (HIV)-infected individuals are unaware of their infection, and stigma and discrimination continue to threaten acceptance of HIV testing services worldwide. Self-testing for HIV has garnered controversy for years and the debate reignited with the approval of a point-of-care test for over-the-counter sale in the US in 2012. Here, we present arguments for and against HIV self-testing. The case in support of HIV self-testing contends that: the modality is highly acceptable, especially among the most at-risk individuals; self-testing empowers users, thus helping to normalize testing; and mutual partner testing has the potential to increase awareness of risk and avert condomless sex between discordant partners. Arguments against HIV self-testing include: cost limits access to those who need testing most; false-negative results, especially during the window period, may lead to false reassurance and could promote sex between discordant partners at the time of highest infectivity; opportunities for counseling, linkage to care, and diagnosis of other sexually transmitted infections may be missed; and self-testing leads to potential for coercion between partners. Research is needed to better define the risks of self-testing, especially as performance of the assays improves, and to delineate the benefits of programs designed to improve access to self-test kits, because this testing modality has numerous potential advantages and drawbacks.HIV/AIDS - Research and Palliative Care 08/2014; 6:117-26. DOI:10.2147/HIV.S49083
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ABSTRACT: Background Little is known about the clinical performance of the 2010 APHL/CDC Western-blot independent HIV testing algorithm in low risk pediatric and obstetric patients. Objective To evaluate the performance of an alternate Western-blot independent algorithm and the individual algorithm components in diagnosing HIV infections in low risk pediatric and obstetric patients. Study design: 6242 specimens from pediatric and obstetric patients were tested by the Bio-Rad Multispot HIV-1/HIV-2 (MS) and VITROS Anti HIV 1 + 2 (VITROS) assays. 913 specimens were also tested by the ARCHITECT HIV Ag/Ab Combo assay (ARCHITECT). Discordant specimens were tested by the APTIMA HIV-1 RNA Qualitative assay (RNA Qual). Results Twenty-eight specimens tested positive for HIV-1 by both MS and VITROS, 4 of these 28 specimens were also tested by and positive by ARCHITECT; all 28 positives identified by the algorithm were positive by viral load analysis. MS identified 164 preliminary positives, which were not confirmed as true positives, representing a specificity of 97.4%. This specificity varied between patient populations (96.1% in the pediatric population and 99.1% in the obstetric population). The specificities of VITROS and ARCHITECT were 99.2% and 99.4% for pediatric patients; 99.7% and 99.8% for obstetric patients respectively. Conclusion Our results highlight suboptimal specificity of MS in pediatric patients, and a lower specificity in both pediatric and obstetric patients relative to either VITROS or ARCHITECT. Additionally, parallel testing with both a third and fourth generation EIA in a low risk patient population provides a potential alternative to Western-blot dependent algorithms for confirmation.Journal of Clinical Virology 11/2014; 61(3). DOI:10.1016/j.jcv.2014.08.007 · 3.47 Impact Factor